It's dead but still around. This is the stuff ripe for Jia Tan v4.0 to revive and backdoor.
Frankly, this Obj-C effort needed to be done way earlier, starting with AppKit, like back when Microsoft was panicking that OS X 10.4 Tiger was going to kick Longhorn's butt. If these tools had already been proven useful before the dawn of the iPhone, Microsoft might have had a chance of riding the iOS wave.
Would have been good if someone made bindings for them, it would have been interesting to see what MacOS like stuff could work there, even if it just python bindings.
IIRC it was actually this Windows port of Toolbox that in some ways laid the foundation for Carbon - i.e. a port of the Toolbox API to what became Mac OS X.